Configuring Apache PHP settings …
… done
Applying web server configuration …
… done
Now installing WHMCS version 4.5.2 …
Failed to fetch system check page : HTTP/1.1 500 Internal Server Error
More information on using this script can be found at http://www.whmcs.com/members/aff.php?aff=4115.
… installation was only partially complete.
Re-loading Webmin …
… done
[Thu Aug 25 17:04:22 2011] [warn] (104)Connection reset by peer: mod_fcgid: read data from fastcgi server error.
[Thu Aug 25 17:04:22 2011] [error] [client XX.XX.XX.XXX] Premature end of script headers: install.php
[Thu Aug 25 17:05:07 2011] [warn] (104)Connection reset by peer: mod_fcgid: read data from fastcgi server error.
[Thu Aug 25 17:05:07 2011] [error] [client XX.XX.XX.XXX] Premature end of script headers: index.php
I do have an ,htaccess file in the root directory, but it just has some simple redirects and anti-leeching lines in it.
It seems to me that the 500 error might have something to do with the changes the script makes to php.ini. I say this because even after I remove the failed install, I still get a 500 error when visiting the Joomla site on that account - until I restore php.ini.